The present invention relates generally to cooling systems. More particularly, the present invention relates to cooling systems for regulating the temperature of electronic components of electronic devices. The present invention is particularly, but not exclusively, useful for cooling systems that regulate the temperature of electronic components of blade servers.
The regulation of the temperature of electronic components like processors due to heat generated inside the housing of an electronic device like a blade server is an important consideration during the design of an electronic device. Cooling is important because if left unchecked, heat can cause electronic devices to malfunction during use or lead to premature device failure. As improvements in processor speed occur, the amount of heat generated by the faster processors also increases. Additionally, improved processors require larger power supplies and auxiliary components that generate increased amounts of heat and require improved systems for heat removal.
Another factor that aggravates the need for improved heat removal cooling systems is the trend towards making computing devices such as blade servers smaller and especially thinner. The trend toward smaller and thinner electronic devices having larger, faster processors renders the traditional heat removal cooling systems inadequate for several reasons. First, smaller devices having faster processors result in an increased density of heat producing by electronic components leading to higher concentrations of heat. Second, a decreased amount of space is available for temperature regulating devices such as traditional heatsinks. Lastly, a decreased amount of space is available to create ventilation paths that pass through the heat-exchanging channels of the heatsink. Thus, traditional blower assemblies having an inlet from above the blower that ventilate the entire housing of the device are less effective or inapplicable in removing heat when used in smaller, thinner devices.
There are numerous designs of cooling systems for electronic devices that include a blower-assisted heatsink located directly at the electronic component. These conventional coolers had been using axial or radial blowers primarily. But, in spite of relatively high blower efficiency at regular size of axial and radial blowers, the blower efficiency drops dramatically when these blowers have been used for relatively small size cooling systems.
There are known devices of this type, for example, U.S. Pat. No. 6,196,300 “Heatsink”. The device described in this US patent comprises an axial blower that produces a flow passing by heat-exchanging channels of the heatsink. The majority of inlets of the heat-exchanging channels are located just opposite of the axial blower's impeller with a certain number of said channels being placed radially in relation to the impeller axle.
The axial blower produces sufficient air pressure. However, due to the weak airflow in the area adjacent to the blower axle, the conditions for cooling of the central part of the heatsink located underneath a hub of the fan are unfavorable. In this case non-uniform cooling of the heatsink and electronic components will take place. It does not allow obtaining good efficiency for the heat-exchange process.
U.S. Pat. No. 5,838,066 “Miniaturized cooling fan type heatsink for semiconductor device” offers a design employing a radial blower that is installed on the side of the heatsink. In one particular embodiment of this invention the cooling airflow passes by rectilinear means through the heat-exchanging channels of the heatsink.
However, placement of a radial blower to the side of the heatsink increases the device size and reduces its effectiveness because the location of the radial blower leads to insufficient coordination between the direction of channel inlets and direction of airflow supplied from the blower.
An invention described in the patent of Japan No. 8-195,456 “Cooler for electronic apparatus” comprises heatsink, a radial blower enclosed in the casing and an electric drive located out of the casing. The blower is installed above the heat-exchanging channels of the heatsink. Another heatsink surface is made so that the possibility of thermal contact with an electronic device is provided for. The inlet of the radial blower faces the heatsink. The radial blower produces an airflow that passes by the heat-exchanging channels and then gets drawn into the inlet of said blower.
It is also known a cooler for electronic components described on: http://www.dynatron-corp.com/products/cpucooler/1USolution.asp? page=1U, -DC1U-B04 for AMD K8 Opteron Socket or DC1U-B01 for AMD Socket A/462, INTEL Socket 370. This cooler is the same like the cooler according to the above Japanese Patent but has only one difference—the electric drive being located inside the blower and surrounded by the impeller thus decreasing the thickness of the cooler but the same time decreasing the blower efficiency.
The main problem of all coolers with a radial blower-assisted heatsink—not enough thermal efficiency of the cooler with fixed overall sizes because of not enough heat-exchanging surface.
Therefore, it would be generally desirable to provide an apparatus that overcomes this problem associated with a cooler comprising a blower-assisted heatsink and has higher thermal efficiency without the need to increase the size of the cooler.